Purchase recommendation bathtub with backrest

Can one generally say that metal trays are better than plastic ones?

Can one generally say that metal pans are better than plastic ones?

No, both have advantages as well as disadvantages.

Exactly, both materials have their advantages and disadvantages. For example, we have a Hoesch Happy D made of [Sanitäracryl] and cannot say anything negative about it. Of course, [Sanitäracryl] is a bit more susceptible to small scratches, but the metal tub is usually a bit cooler. However, we are satisfied!

Would you install with or without [Wannenträger]?

I wouldn't install anything myself, only have it installed. And that by a professional who installs everything according to the latest state of the art. If with a support beam, then with a support beam... I don't have to decide that as a layperson. It probably also depends on the material of the [Wanne]?!